我创建了一个图片库应用。我可以使用我的应用选择图像并返回显示所有文件夹但无法使用我的应用移动它们的活动。 我想选择多个图像，单击 buttoncut 并返回显示所有文件夹的活动（ImageGallery.java）。现在，我想选择一个文件夹并将所有选定的图像粘贴到该文件夹中。如何实现这一目标？
ImageGallery.java （显示所有文件夹的活动）
public class ImageGallery extends AppCompatActivity {
public static ArrayList<Model_images> al_images = new ArrayList<>();
boolean boolean_folder;
Adapter_PhotosFolder obj_adapter;
GridView gv_folder;
private static final int REQUEST_PERMISSIONS = 100;
int int_position;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_image_gallery);
gv_folder = (GridView) findViewById(android.R.id.list);
obj_adapter = new Adapter_PhotosFolder(this,al_images,int_position);
gv_folder.setAdapter(obj_adapter);
final ImageButton buttonpaste = (ImageButton) findViewById(R.id.buttonpaste);
buttonpaste.setVisibility(View.GONE);
final ImageButton buttoncut = (ImageButton) findViewById(R.id.button1);
final ImageButton button2 = (ImageButton) findViewById(R.id.button2);
final ImageButton button3 = (ImageButton) findViewById(R.id.button3);
final ImageButton button4 = (ImageButton) findViewById(R.id.button4);
final ImageButton button5 = (ImageButton) findViewById(R.id.button5);
buttoncut.setVisibility(View.GONE);
button2.setVisibility(View.GONE);
button3.setVisibility(View.GONE);
button4.setVisibility(View.GONE);
button5.setVisibility(View.GONE);
gv_folder.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Intent intent = new Intent(getApplicationContext(), PhotosActivity.class);
intent.putExtra("value",i);
startActivity(intent);
}
});
gv_folder.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> adapterView, View view,final int i, long l) {
for (int j = 0; j < adapterView.getChildCount(); j++)
adapterView.getChildAt(j).setBackgroundColor(Color.TRANSPARENT);
// change the background color of the selected element
view.setBackgroundColor(Color.LTGRAY);
buttoncut.setVisibility(View.VISIBLE);
button2.setVisibility(View.VISIBLE);
button3.setVisibility(View.VISIBLE);
button4.setVisibility(View.VISIBLE);
button5.setVisibility(View.VISIBLE);
buttoncut.setOnClickListener(
new View.OnClickListener(){
public void onClick(View view){
buttoncut.setVisibility(View.GONE);
button2.setVisibility(View.GONE);
button3.setVisibility(View.GONE);
button4.setVisibility(View.GONE);
button5.setVisibility(View.GONE);
buttonpaste.setVisibility(View.VISIBLE);
}
});
button2.setOnClickListener(
new View.OnClickListener(){
public void onClick(View view){
buttoncut.setVisibility(View.GONE);
button2.setVisibility(View.GONE);
button3.setVisibility(View.GONE);
button4.setVisibility(View.GONE);
button5.setVisibility(View.GONE);
buttonpaste.setVisibility(View.VISIBLE);
}
});
button3.setOnClickListener(
new View.OnClickListener() {
public void onClick(View view) {
AlertDialog.Builder builder1 = new AlertDialog.Builder(ImageGallery.this);
builder1.setMessage("Are you sure you want to delete it ?");
builder1.setCancelable(true);
builder1.setPositiveButton(
"Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
File file = new File(al_images.get(int_position).getAl_imagepath().get(i));
file.delete();
MediaScannerConnection.scanFile(ImageGallery.this,new String[] { file.toString() }, null,
new MediaScannerConnection.OnScanCompletedListener() {
public void onScanCompleted(String path, Uri uri) {
Log.i("ExternalStorage", "Scanned " + path + ":");
Log.i("ExternalStorage", "-> uri=" + uri);
}
});
al_images.remove(i);
obj_adapter.notifyDataSetChanged();
finish();
}
});
builder1.setNegativeButton(
"No",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert11 = builder1.create();
alert11.show();
}
});
return true;
}
});
if ((ContextCompat.checkSelfPermission(getApplicationContext(),
Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) && (ContextCompat.checkSelfPermission(getApplicationContext(),
Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)) {
if ((ActivityCompat.shouldShowRequestPermissionRationale(ImageGallery.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) && (ActivityCompat.shouldShowRequestPermissionRationale( ImageGallery.this,
Manifest.permission.READ_EXTERNAL_STORAGE))) {
} else {
ActivityCompat.requestPermissions( ImageGallery.this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE},
REQUEST_PERMISSIONS);
}
}else {
Log.e("Else","Else");
fn_imagespath();
}
}
public ArrayList<Model_images> fn_imagespath() {
al_images.clear();
int int_position = 0;
Uri uri;
Cursor cursor;
int column_index_data, column_index_folder_name;
String absolutePathOfImage;
uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
String[] projection = {MediaStore.MediaColumns.DATA, MediaStore.Images.Media.BUCKET_DISPLAY_NAME};
final String orderBy = MediaStore.Images.Media.DATE_TAKEN;
cursor = getApplicationContext().getContentResolver().query(uri, projection, null, null, orderBy + " DESC");
column_index_data = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
column_index_folder_name = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
while (cursor.moveToNext()) {
absolutePathOfImage = cursor.getString(column_index_data);
Log.e("Column", absolutePathOfImage);
Log.e("Folder", cursor.getString(column_index_folder_name));
for (int i = 0; i < al_images.size(); i++) {
if (al_images.get(i).getStr_folder().equals(cursor.getString(column_index_folder_name))) {
boolean_folder = true;
int_position = i;
break;
} else {
boolean_folder = false;
}
}
if (boolean_folder) {
ArrayList<String> al_path = new ArrayList<>();
al_path.addAll(al_images.get(int_position).getAl_imagepath());
al_path.add(absolutePathOfImage);
al_images.get(int_position).setAl_imagepath(al_path);
} else {
ArrayList<String> al_path = new ArrayList<>();
al_path.add(absolutePathOfImage);
Model_images obj_model = new Model_images();
obj_model.setStr_folder(cursor.getString(column_index_folder_name));
obj_model.setAl_imagepath(al_path);
al_images.add(obj_model);
}
}
for (int i = 0; i < al_images.size(); i++) {
Log.e("FOLDER", al_images.get(i).getStr_folder());
for (int j = 0; j < al_images.get(i).getAl_imagepath().size(); j++) {
Log.e("FILE", al_images.get(i).getAl_imagepath().get(j));
}
}
obj_adapter = new Adapter_PhotosFolder(getApplicationContext(),al_images,int_position);
gv_folder.setAdapter(obj_adapter);
return al_images;
}
PhotosActivity.java （在文件夹中显示图片的活动）：
import static com.example.dell_1.myapp3.ImageViewer.ImageGallery.al_images;
public class PhotosActivity extends AppCompatActivity {
int int_position;
private GridView gridView;
GridViewAdapter adapter;
ArrayList<Model_images> al_menu = new ArrayList<>();
private ArrayList<Integer> mSelected = new ArrayList<>();
boolean boolean_folder;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_image_gallery);
final ImageButton buttoncut = (ImageButton) findViewById(R.id.button1);
final ImageButton button2 = (ImageButton) findViewById(R.id.button2);
final ImageButton button3 = (ImageButton) findViewById(R.id.button3);
final ImageButton button4 = (ImageButton) findViewById(R.id.button4);
final ImageButton button5 = (ImageButton) findViewById(R.id.button5);
final ImageButton buttonpaste = (ImageButton) findViewById(R.id.buttonpaste);
buttoncut.setVisibility(View.GONE);
button2.setVisibility(View.GONE);
button3.setVisibility(View.GONE);
button4.setVisibility(View.GONE);
button5.setVisibility(View.GONE);
buttonpaste.setVisibility(View.GONE);
gridView = (GridView) findViewById(android.R.id.list);
int_position = getIntent().getIntExtra("value", 0);
adapter = new GridViewAdapter(this, al_images, int_position);
gridView.setChoiceMode(AbsListView.CHOICE_MODE_MULTIPLE);
gridView.setAdapter(adapter);
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String abc = "file://" + al_images.get(int_position).getAl_imagepath().get(position);
Intent i = new Intent(getApplicationContext(), FullImageActivity.class);
i.putExtra("id", position);
i.putExtra("folderPosition", int_position);
i.putExtra("abc", abc);
startActivity(i);
}
});
gridView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(final AdapterView<?> parent, View view, final int position, long id) {
if(mSelected.contains(position)) {
mSelected.remove(position);
view.setBackgroundColor(Color.TRANSPARENT);// remove item from list
// update view (v) state here
// eg: remove highlight
}
else {
mSelected.add(position);
view.setBackgroundColor(Color.LTGRAY);// add item to list
// update view (v) state here
// eg: add highlight
}
buttoncut.setVisibility(View.VISIBLE);
button2.setVisibility(View.VISIBLE);
button3.setVisibility(View.VISIBLE);
button4.setVisibility(View.VISIBLE);
button5.setVisibility(View.VISIBLE);
buttoncut.setOnClickListener(
new View.OnClickListener(){
public void onClick(View view){
buttoncut.setVisibility(View.GONE);
button2.setVisibility(View.GONE);
button3.setVisibility(View.GONE);
button4.setVisibility(View.GONE);
button5.setVisibility(View.GONE);
startActivityB();
}
});
button2.setOnClickListener(
new View.OnClickListener(){
public void onClick(View view){
buttoncut.setVisibility(View.GONE);
button2.setVisibility(View.GONE);
button3.setVisibility(View.GONE);
button4.setVisibility(View.GONE);
button5.setVisibility(View.GONE);
startActivityB();
}
});
button3.setOnClickListener(
new View.OnClickListener() {
public void onClick(View view) {
AlertDialog.Builder builder1 = new AlertDialog.Builder(PhotosActivity.this);
builder1.setMessage("Are you sure you want to delete it ?");
builder1.setCancelable(true);
builder1.setPositiveButton(
"Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
adapter.updateUpdater(mSelected);
for(int position=0;position<mSelected.size();position++) {
al_images.get(int_position).getAl_imagepath().remove(position);
}
finish();
}
});
builder1.setNegativeButton(
"No",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert11 = builder1.create();
alert11.show();
}
});
return true;
}
});
}
private void startActivityB() {
Intent intent = new Intent(PhotosActivity.this,ImageGallery.class);
startActivity(intent);
}
答案 0 :(得分：1)
移动/复制您可以使用以下代码段的文件。
private void copyOrMoveFile(File file, File dir,boolean isCopy) throws IOException {
File newFile = new File(dir, file.getName());
FileChannel outChannel = null;
FileChannel inputChannel = null;
try {
outChannel = new FileOutputStream(newFile).getChannel();
inputChannel = new FileInputStream(file).getChannel();
inputChannel.transferTo(0, inputChannel.size(), outChannel);
inputChannel.close();
if(!isCopy)
file.delete();
} finally {
if (inputChannel != null) inputChannel.close();
if (outputChannel != null) outputChannel.close();
}
}
确保在剪切或移动的情况下，您必须删除源文件。